TUESDAY, Nov. 28, 2017 (HealthDay News) -- More doctors in the United States are turning to a new clinical specialty -- nursing home care.

The number of physicians and health care providers concentrating on nursing home patients grew by about one-third between 2012 and 2015, researchers from the University of Pennsylvania School of Medicine found.

The trend is likely driven by the aging population and increased federal government oversight of nursing homes, the researchers said.

"We don't know how this trend will play out in the long term, but nursing home specialists have the potential to change the way health care is delivered in this setting," said lead author Dr. Kira Ryskina, an assistant professor at UPenn.

"On one hand, clinicians who practice in the nursing home exclusively could improve patient outcomes and reduce costs by leveraging expertise in nursing home processes of care, for example," Ryskina said in a university news release.

"But concentrating patient care among nursing home specialists could also mean that patients are no longer seen by their primary care providers, who traditionally follow patients for years and across care settings," Ryskina added.

Nursing home specialists were defined as people for whom nursing home care accounts for at least 90 percent of their billing.

Analyzing Medicare data, the researchers found that the number of doctors, nurse practitioners and physician assistants who were nursing home specialists rose from about 5,100 in 2012 to more than 6,800 in 2015 -- about 34 percent.

During that same period, there was little change in the overall number of these health care providers billing from nursing homes -- 33,218 to 33,087.

Of all health care providers who do any work in nursing homes, 21 percent now "specialize" in nursing home care, according to the study.

The findings were published Nov. 28 in the Journal of the American Medical Association.

There are more than 15,000 nursing homes in the United States, with a total capacity of nearly 1.7 million beds. Because of a wide variation in the quality of health care, the U.S. Centers for Medicare and Medicaid Services has proposed reforms and penalties for low-quality care.

The nursing home industry may now be adapting to closer government oversight by employing physicians who specialize in nursing home care, according to the study authors.

Hospitals did something similar over the past two decades, the researchers pointed out.

"Hospitals in recent years have sought to improve care by concentrating it among 'hospitalist' physicians who focus on treating hospitalized patients," Ryskina said.

"Twenty years ago, the hospitalist movement started in the same way, wherein hospitals were under pressure to reduce costs, and readmissions. We might be seeing the beginnings of a similar trend in nursing home care," Ryskina added.